In emissive display screens, such as organic light emitting diode (OLED) display screens, the luminance of the individual light-emitting pixels degrades over time. The rate of degradation of a particular pixel depends upon the frequency of usage of the pixel as it ages. That is, the more frequently a pixel is activated, the more quickly the pixel will wear out and lose its luminance. Furthermore, the rate of degradation is different for the three primary colors. Some pixels (among the thousands to millions of pixels) within a display will be used more often than other pixels over time. The uneven degradation of luminance between different pixels in a display can produce undesirable effects such as color shift and/or burn-in patterns (also known as image sticking).
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